Performance of mild steel perforated plates as a blast wave mitigation technique

This article presents the results of an experimental and numerical investigation into the influence of hole size and thickness on the performance of mild steel perforated plates as a blast wave mitigation technique. Results of the blast tests showed that the perforated plates with small hole sizes reduced the damage imparted to the target plate by reducing the target plate mid-point deflection and increasing the tearing threshold impulse. Ansys Autodyn was used to model the experiments and the perforated plate hole diameter was varied during the simulations. The impulse imparted to the pendulum, target plate and perforated plate deflections compared favourably to the experimental results. The modelling simulations also gave further insight into the interaction between the blast wave and the plates. The simulations showed that the impulse imparted to the target plate was higher than the impulse measured from the experimental pendulum swing and that the difference increased with increasing blockage ratio. The simulations also showed that the total load duration was much longer than the response time of the plate, indicating that a proportion of the impulse does not contribute to the deformation of the target plate. The response time was shown to increase with increasing blockage ratio and decrease with increasing impulse.